package likouJava;

import java.util.HashMap;
import java.util.Map;

public class 两数之和 {
    //暴力算法
    public int[] twoSum(int[] nums,int target){
        int n = nums.length;
        for(int i=0;i<n;i++){
            for(int j=1;j<n;j++){
                if (nums[i] + nums[j] == target){
                    return new int[]{i,j};
                }
            }
        }
        return new int[0];
    }
}


class Solution {
    //哈希表算法
    public int[] twoSum(int[] nums, int target) {
        Map<Integer,Integer> hashtable = new HashMap<Integer,Integer>();
        for(int i =0;i< nums.length;i++){
            if(hashtable.containsKey(target - nums[i])){
                return new int[]{i,hashtable.get(target - nums[i])};
            }
            hashtable.put(nums[i],i);
        }
        return new int[0];
    }
}